Synthesis and luminescent properties of red-emitting phosphors: ZnSiF6·6H2O and ZnGeF6·6H2O doped with Mn4+

A simple method for the synthesis of red emitting Mn4+ activated phosphors is presented. The crystal structure of ZnGeF6·6H2O was determined by single crystal X-ray diffraction and was isotopic with NiSnCl6·6H2O (space group Rimage). Luminescent properties of ZnSiF6·6H2O and ZnGeF6·6H2O doped with manganese(IV) at different concentration levels were studied. The optimal Mn4+ concentration with respect to the emission intensity was found to be 5 mol% for ZnSiF6·6H2O and 3 mol% for ZnGeF6·6H2O.